/*
 * Copyright 2023-2024 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.pig4cloud.pigx.common.core.util;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StreamUtils;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Map;

/**
 * Request包装类：允许 body 重复读取
 *
 * @author Hccake
 */
@Slf4j
public class RepeatBodyRequestWrapper extends HttpServletRequestWrapper {

    private final byte[] bodyByteArray;

    private final Map<String, String[]> parameterMap;

    public RepeatBodyRequestWrapper(HttpServletRequest request) {
        super(request);
        this.bodyByteArray = getByteBody(request);
        this.parameterMap = super.getParameterMap();
    }

    @Override
    public BufferedReader getReader() {
        return ObjectUtils.isEmpty(this.bodyByteArray) ? null
                : new BufferedReader(new InputStreamReader(getInputStream()));
    }

    @Override
    public ServletInputStream getInputStream() {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(this.bodyByteArray);
        return new ServletInputStream() {
            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {
                // doNoting
            }

            @Override
            public int read() {
                return byteArrayInputStream.read();
            }
        };
    }

    private static byte[] getByteBody(HttpServletRequest request) {
        byte[] body = new byte[0];
        try {
            body = StreamUtils.copyToByteArray(request.getInputStream());
        }
        catch (IOException e) {
            log.error("解析流中数据异常", e);
        }
        return body;
    }

    /**
     * 重写 getParameterMap() 方法 解决 undertow 中流被读取后，会进行标记，从而导致无法正确获取 body 中的表单数据的问题
     * @return Map<String, String [ ]> parameterMap
     */
    @Override
    public Map<String, String[]> getParameterMap() {
        return this.parameterMap;
    }

}
